Transmission Slip

[alan300]

Hey everyone,

 

Over the past few months, I've noticed my 05 Z71 Crew transmission slipping. This has only occurred while sitting at a stop light.

 

Has anyone else experienced this? I dread taking it in because I'm afraid it will never be the same once I get it back. It's only done it about 5 times in the last year. I'll be sitting at the stop light, it will turn green, I'll ease the gas pedal down, and the engine will rev but not go, then about 2 seconds later, it clicks and then goes. Scary.

 

Is this a bad sign for things to come?

 

Thanks,

[Jansen]

Very common occurance. We (myself included) just had this discussion last week. Search for trans slip and you'll find the post it has some good info in it. My '04 has this. I've seen it 4 times in 34,000 miles. It is scary but correctable (I think). This is the service bulletin for this, found in the original "trans slip on occasion" post, Aug 29 time frame.

 

***************************

As quoted from CaptialTruck:

 

Subject: 4L60-E/4L65-E Automatic Transmission Second Gear Start, Lack/Loss of Power When Accelerating from a Stop (Reprogram Powertrain Control Module (PCM)) #05-07-30-013 - (05/09/2005)

 

 

 

Models: 2004-2005 Cadillac Escalade

 

2004-2005 Chevrolet Avalanche, Express, Silverado, Suburban, Tahoe

 

2004-2005 GMC Savana, Sierra, Yukon

 

2004-2005 HUMMER H2

 

with 4L60-E (RPO M30) or 4L65-E (RPO M32) Automatic Transmission

 

 

 

 

--------------------------------------------------------------------------------

 

Condition

Some customers may comment on a slip on launch, low power on a launch or a second gear start when accelerating from a stop.

 

This condition is usually very intermittent, occurring only once in a few thousand miles of driving.

 

A Tech 2 or VDR snapshot of the event may show 2nd gear being commanded for approximately two seconds, then 1st gear commanded as would be expected.

 

Cause

This condition may be caused by an intermittent VSS signal, which causes the PCM to command second gear.

 

Important: There are other conditions that can cause the transmission to start in a gear higher than first. The following are a few of these conditions.

 

• Some DTCs can cause the transmission to start in a higher gear. Check for the presence of DTCs and repair as appropriate before proceeding.

 

• Debris on top of the spacer plate or in the valve body or a leaking shift solenoid can cause a 4L60-E or 4L65-E transmission to start in a gear higher than first. A start in a higher gear caused by any of these conditions typically occurs with much greater frequency. Refer to Service Bulletin 01-07-30-036D or newer for diagnostic information of these conditions.

 

• Placing the shift lever in the D2 position will cause a 4L60-E or 4L65-E transmission to start in second gear.

 

 

Correction

Important:

 

• This bulletin ONLY applies to 2004-2005 models year vehicles listed above.

 

• Some DTCs can cause the transmission to start in a higher gear. Check for the presence of DTCs and repair as appropriate before proceeding.

 

 

Using a scan tool, check for the presence of DTCs. If DTCs are present, refer to the appropriate SI Document before proceeding with this calibration.

Important: These calibrations also contain the 2-3 shift clunk calibration as detailed in bulletin 05-07-30-012.

 

Technicians are to reprogram the PCM with an updated software calibration. This new service calibration was released with TIS satellite data update version 5 or later available May 1, 2005. Refer to Service Programming System (SPS) in Vehicle Control Systems in the appropriate SI Document.

***************

 

Jansen

[alan300]

Very common occurance.  We (myself included) just had this discussion last week. Search for trans slip and you'll find the post it has some good info in it. My '04 has this.  I've seen it 4 times in 34,000 miles.  It is scary but correctable (I think).  This is the service bulletin for this, found in the original "trans slip on occasion" post, Aug 29 time frame.

 

***************************

As quoted from CaptialTruck:

 

Subject: 4L60-E/4L65-E Automatic Transmission Second Gear Start, Lack/Loss of Power When Accelerating from a Stop (Reprogram Powertrain Control Module (PCM)) #05-07-30-013 - (05/09/2005)

 

 

 

Models: 2004-2005 Cadillac Escalade

 

2004-2005 Chevrolet Avalanche, Express, Silverado, Suburban, Tahoe

 

2004-2005 GMC Savana, Sierra, Yukon

 

2004-2005 HUMMER H2

 

with 4L60-E (RPO M30) or 4L65-E (RPO M32) Automatic Transmission

 

 

 

 

--------------------------------------------------------------------------------

 

Condition

Some customers may comment on a slip on launch, low power on a launch or a second gear start when accelerating from a stop.

 

This condition is usually very intermittent, occurring only once in a few thousand miles of driving.

 

A Tech 2 or VDR snapshot of the event may show 2nd gear being commanded for approximately two seconds, then 1st gear commanded as would be expected.

 

Cause

This condition may be caused by an intermittent VSS signal, which causes the PCM to command second gear.

 

Important: There are other conditions that can cause the transmission to start in a gear higher than first. The following are a few of these conditions.

 

• Some DTCs can cause the transmission to start in a higher gear. Check for the presence of DTCs and repair as appropriate before proceeding.

 

• Debris on top of the spacer plate or in the valve body or a leaking shift solenoid can cause a 4L60-E or 4L65-E transmission to start in a gear higher than first. A start in a higher gear caused by any of these conditions typically occurs with much greater frequency. Refer to Service Bulletin 01-07-30-036D or newer for diagnostic information of these conditions.

 

• Placing the shift lever in the D2 position will cause a 4L60-E or 4L65-E transmission to start in second gear.

 

 

Correction

Important:

 

• This bulletin ONLY applies to 2004-2005 models year vehicles listed above.

 

• Some DTCs can cause the transmission to start in a higher gear. Check for the presence of DTCs and repair as appropriate before proceeding.

 

 

Using a scan tool, check for the presence of DTCs. If DTCs are present, refer to the appropriate SI Document before proceeding with this calibration.

Important: These calibrations also contain the 2-3 shift clunk calibration as detailed in bulletin 05-07-30-012.

 

Technicians are to reprogram the PCM with an updated software calibration. This new service calibration was released with TIS satellite data update version 5 or later available May 1, 2005. Refer to Service Programming System (SPS) in Vehicle Control Systems in the appropriate SI Document.

***************

 

Jansen

 

<{POST_SNAPBACK}>

 

 

 

Thank you Janen,

 

Looks like I'm gonna have to make a trip to the dealer sometime. Argh.

[MAGNUM]

I was talking to a friend the other day about the slipping in my 05 yukon xl and he recommended that I take out the mass air flow sensor from the intake tube and clean it really well with ether. I haven't tried it yet, but who knows, he claimed it fixed his.